Polymerization processes for producing polymers, such as polyolefins, may be highly exothermic, thus, requiring removal of heat during the polymerization process. Typically, shell and tube heat exchangers have been used to remove heat from polymerization processes. For example, U.S. Pat. No. 5,977,251 generally discloses a polymerization process utilizing one or more shell and tube heat exchangers. However, there is a high pressure drop associated with shell and tube heat exchangers due to the high volume capacity needed to provide sufficient surface area for heat transfer in shell and tube heat exchangers. Also, a shell and tube heat exchanger may further require internal structures or static mixers to achieve an acceptable heat transfer coefficient, which increases the already high pressure drop resulting in limited recirculation rates and production rates.
WO 00/61644 discloses a method for continuously producing polymers comprised of vinyl aromatic compounds by means of mass polymerization or solvent polymerization, whereby the feed materials are fed into a spiral heat exchanger and are reacted therein. Other references of interest include: EP 0 926 161; WO 97/36942; U.S. Pat. No. 5,977,251; WO 2015/040522; U.S. Pat. No. 8,431,096; U.S. Pat. No. 8,153,757; and U.S. Pat. No. 8,153,757.
Thus, there is a need in the art for new and improved polymerization processes, which are capable of sufficient heat removal so as not to significantly affect production rates. It is therefore an object of the present invention to provide polymerization processes where the sufficient removal of heat from the reaction is achieved by heat exchangers with increased heat transfer capabilities, smaller footprints, and lower pressure drops.